Hello all, Currently, we have \ior_open:Nn for reading from a file, but no defined interface for using the 'pipe' shell escape provided by pdfTeX. As we forbid spaces in file names, something like \ior_open:Nn \g_some_ior {"|kpsewhich~-all~file.tex"} fails with an error. A defined interface("\ior_pipe:Nn") has been suggested (http://chat.stackexchange.com/transcript/message/15666333#15666333). Thoughts on the concept/naming/etc.? Note that this is opening a pseudo-file so does need to be related in some way to \ior_open:Nn. -- Joseph Wright